http://www.youtube.com/watch?gl=NG&feature=plcp&hl=en-GB&v=wu5v8mahw18

Well according to this video i can get a really good armor at lvl 0 but i got a question anybody know where it is that you can get that key?

And where it is he´s going??

It's on the plateau overlooking Old Camp from the south side.
He is going to old Xardas tower, which got flooded (also in the southern part of the map).

Story wise, what he's doing is game-breaking, since Xardas sends you there and thus gives you the key, and I won't say anything about a complete lost sense of progress, which makes Gothic so beautiful.

Edit:
You can have a look at game maps here.